Continuous feed brake shoe grinding fixture



1951 F. A. HARPER ET AL CONTINUOUS FEED BRAKE SHOE GRINDING FIXTURE 'Filed Oct. 7, 1949 2 SI-lEETS Sl-IEET l M. mm E0, .4 U a we I n A W m A K w M mw W x w a i a 7 a 1 4 u N 1951. F. A. HARPER ET AL CONTINUOUS FEED BRAKE SHOE GRINDING FIXTURE Filed Oct. 7, 1949 2 SHEETSSHEET 2 villi 1114 INVENTOR. FHA/W104, HA/FPf/Q y (/a/m/ M GW/I/IAM.

Patented Nov. 13, 1951 CONTINUOUS FEED BRAKE SHOE GRINDING FIXTURE Frank A. Harper and John M. Graham, Paulding, Ohio Application October 7, 1949, Serial No. 120,074

3 Claims. (Cl. 51-108) This invention relates to improved apparatus for removing brake lining from automotive brake shoes, the primary object of the invention being to provide efiicient and relatively low-cost, powerdriven apparatus of this character employing magnetic feed wheels for mounting and feeding a brake shoe against a grinding wheel or other abrasive agent, the feed wheels being of different diameters to accommodate different sizes of brake shoes.

Another important object of the invention is to provide apparatus of the character indicated above wherein the feed wheels have locking means actuated by rotation of the wheels to secure the brake shoes in place thereon during removal of the brake lining; meansfor releasing the locking means upon rotation of the wheels to positions in which the lining-removal operation has been completed; and ejecting means acting to remove the brake shoes from the feed wheels upon completion of the lining-removal operation.

Another important object of the invention is the provision of apparatus of the above-indicated character which acts to clean and recondition the face of the brake shoe while removing the lining therefrom, and in which provision is made for operation of the feed wheel at slow, intermediate or high speeds. Y

A further important object ofthe invention is the provision of apparatus of the character indicated above which can be built with integral abrasive or cutting means or which can be provided as a power-driven feed wheel attachment adapted to be applied to existing abrasive or cutting means.

Other important objects and advantageous features of the invention will be apparent from the following description and the accompanying drawings wherein, for purposes of illustration only, specific embodiments of the invention are set forth in detail.

In the drawings:

Figure 1 is arear end elevation of one embodiment;

Figure 2 is a fragmentary right-hand side elevation thereof; partly in section;

Figure 3 is an enlarged fragmentary detail of the feed wheel, showing the brake shoe in section and clamped or locked therein;

Figure 4 is a fragmentary right-hand side elev'ation, with the outer feed wheel disc removed;

Figure 5 is a transverse vertical section taken on the line 5-5 of Figure 2;

Figure 6 is a horizontal section taken on the line 6-6 of Figure 2 Figure 7 is a fragmentary right-hand side elevation, showing the graduated hand wheel enabling vernier adjustment of the approach of the feed wheel to the grinding wheel;

Figure 8 is a fragmentary right-hand side elevation of another embodiment involving different brake shoe locking means showing application of a brake shoe on the feed wheel to the grinding wheel;

Figure 9 is an enlarged, fragmentary exploded view of said different brake shoe locking means;

Figure 10 is a fragmentary right-hand side elevation of Figure 9.

Referring in detail to the drawings, wherein like numerals desigate like parts throughout the several views, and in particular to Figures 1 to 8 thereof, the numeral l2 generally designates the base adapted to be secured on a suitable support (not shown) and comprising a plate I3 having risers I4 and I5 at its forward and rearward ends, and an intermediate riser l6 spaced therebetween. A vernier screw shaft [1 is slidably journaled in the risers. Spaced at opposite sides of the shaft II are slideways I8 on which are slidably mounted the front and rear blocks I9 and 20, respectively, depending from forward and rearward portions of the retracting carriage 2|. In the extreme rearward position of the carriage 2| the rear block 20 engages the rearward base riser I5, as shown in Figure 2. Helical springs 22 are circumposed on the slideways I8 and compressed between the intermediate riser l6 and the rear slide block 20, whereby the carriage 2| is normally urged rearwardly in a direction toward the grinding wheel.

The rearward end of the vernier screw I! is threaded through the front carriage slide block I9, as shown in Figure 6, and has its rear end journaled in the intermediate riser I6 at 23. A vernier hand wheel 24 is pinned on the forward end of the shaft II, as indicated at 25, and a graduated dial 26 is positioned on this shaft between the hand wheel 24 and the forward riser I4. The hand wheel 24 is adapted to be turned in the proper direction to move the carriage 2| away from the grinding wheel against the resistance of the springs 22 and thereby determine the amount of brake lining to be removed by the grinding wheel. The springs 22 serve to enable the proper feeding of out-of-round brake shoes to the grinding wheel and also as cushioning means, preventing damage to the machine by permitting the carriage 2! to yield whenever an object otherwise too large to pass falls between the brake shoe being ground and the grinding wheel.

The retracting carriage 2| comprises the plate 21 having transverse risers 28 and 29 at its forward and rearward ends, respectively. A base plate 30 forming part of the housing or frame 3| rests slidably on the plate 2! and is shorter than the distance between the risers 28 and 29, so that the frame '31| can be shifted along the plate 21 toward and away from the grinding wheel to accommodate feed wheels for brake shoes of different sizes. A spacer block 32 having a handle 33 is adapted to be positioned to take up the space at either end of the base plate '30 and the related one of the risers 28 and 29.

Longitudinal hold-down clamps 34 are bolted at their ends, as indicated at 35, to the risers 28 and 29 and have depending longitudinal ribs 35 engaging in grooves 37 formed in the housing base plate 30, whereby sidewise shifting of the housing or frame 3| relative to the carriage 2| is precluded.

The housing or frame 3! is generally rectan- 'ular in form and has an electric motor 38 mounted on the upper'end thereof having a belt pulley 39 positioned beyond the left-hand side thereof in vertical alignment with a belt pulley 4.0 positioned therebelow on a shaft 4| of a reducing gear 42, which is operatively connected in a conventional manner (not shown) with the feed wheel shaft 43 which projects from the right-hand sideof the housing 3|.

The feed wheel 45 comprises an inner disc '45 having a spacing annulus 41 on its right-hand or outer side, providing a circular recess 48, as shown in Figure 5. The outer disc 49 has on its inner side a flat, cylindrical portion 59 adapted to fit in the recess 48. The inner disc 46 is circumposed directly on the shaft 43 and the outer disc '49 is traversed by a threaded spindle 5| which threads into a threaded bore 52 in the shaft 43, the spindle having a hand wheel 53 on its outer end adapted to be turned to bear against a washer 54 engaging the outer side of the outer disc to clamp the discs together nonrotatabl-y on the feed wheel shaft 43.

The feed wheel discs are substantially solid and have their peripheral edges indented to provide seats for horseshoe permanent magnets 55 having their poles 55 flush with the peripheries of the discs, the magnets being equally spaced around the peripheries of the discs. Between adjacent magnets 55 are radial pivots 51 on which are retainably pivoted segmental, eccentr-ic locking discs 58 with their curved edges substantially concentric with the pivots 51. While disengaged, the locking discs 58, which are aligned in opposed pairs, occupy the positions shown in Figure 1. During actual use, the abrasive wheel ill travels faster than the wheel 45 andthereby produces a tendency for the brake shoe =60 to travel on the feed wheel 45 in a clockwise direction. Since the curved edges of the locking discs 58 engage the web 59 of the brake shoe Be, the movementof the brake shoe causes the paired locking discs 58 to swing toward each other to clamp therebetween the web 59 of a brake-shoe 59 with the magnets 55 acting upon the arcuate flange 6| in which the lining 62 is secured to hold the brake shoe 60 on the periphery of the feed wheel 45.

.A bracket 63 is mounted on the'forward end of the upper part of the frame or housing 3|, as indicated at 64, and projects toward the feed wheel 45 and terminates. in a stub shaft 65 on whichis pivoted the upper or forward end of an ejecting pin or lever 66.

The lever 66 has ,zthje slightly-downwardly, longitudinally-curved form shown in Figure 4, and the upper edge 61 of its forward end is arranged to ride under the spacer annulus 41 of the inner feed wheel disc 46, while the lower edge thereof is tapered at 68 to ride upon portions of a brake shoe on the feed wheel in a manner hereinafter described.

A power-driven grinding wheel 10 is adapted to be suitably supported behind the feed wheel 45 with its axis in horizontal alignment with the axis. of the feed wheel, and the grinding wheel is rotated counterclockwise and faster than the feed wheel, so as to impart a tendency to the brake shoe to travel on the feed wheel in the same clockwise direction as the feed wheel and wedge the locking discs 58. In placing a brake shoe 60 for grinding, the brake shoe is placed on the feed wheel so that the rearward end of the brake shoe flange 6| meets the grinding wheel 10 at or near the center line of the most rearward arc of its traverse. As the feed wheel with 'a brake shoe installed thereon, as described, continues its rotation, the brake shoe 60 passes the grinding wheel 70 and is completely stripped of its lining 62 as well as of any other foreign matter .present on the face of the shoe. As the feed wheel 45 continues its rotation and the brake shoe *66 passes the center line of the lowest arc of its traverse, the eccentric locking discs 58 are released from clamping engagement with the web 59 of the brake shoe 66 by being engaged by the ejecting lever 66, the action of gravity upon the locking discs, the rotation of the feed wheel 45, and the absence of engagement of the brake shoe with the grinding wheel. The position of the brake shoe 60 just prior to ejectment by the lever 66 is clearly shown in phantom in Figure 8 of the drawings. As the feed wheel 45 moves through this position, the cleaned brake shoe is forced against the under side of the ejecting lever 66 and is thereby forced downwardly off the feed wheel 45 against the pull of the magnets 55, to be disposed of as the'operator sees fit.

The amount of material to be removed from a brake shoe is determined by adjusting the carriage 2| toward or away from the grinding wheel 10 by turning the hand wheel 24 so as to turn the micrometer screw I! and move the retracting carriage 2| on the base 2, thereby determining the distance between the feed wheel 45 and the grinding wheel Hi, the amount of the adjustment being shown by the dial 26.

The machine is adapted to recondition brakejustment of the housing 3| relative to the carriage 21.

Referring to Figures 2 and 3, there is therein shown means for more positively and reliably clamping the locking discs 58 against opposite sides of the web 59 of the brake shoe 69. This means takes the form of vertical arms 7| depending at opposite sides of the feed wheel 45 from a bracket 12 secured to the rear of the housing 3|, these arms having arcua-te shoes ?3 onthei lower ends arranged concentrically with respect to the feed wheel 45. The shoes 13 have rounded approach ends '14, positioned to cam the locking discs 58 toward each other into clamping engage" ment with the related sides of the brake shoe web 59, as shown in Figure 3, as the feed wheel rotates clockwise into a position in which the brake shoe 60 is applied to the grinding wheel. When the locking discs concerned pass beyond the exit end of the shoes 13, the locking discs are free to be released in a manner already described hereinabove.

In Figures 8 to is shown another form of brake shoe clamping means, as a substitute for both of the above-described forms of locking disc arrangements. As shown in Figure 9, the inner and outer discs 46 and 49 of the feed wheel 55 are formed with transverse bores 75 opening at their opposite ends in concentric larger-diameter recesses 16 and 11, respectively. A shank 1% slides in each bore and has a circular locking disc 19 on its inward end and a dish-like head 80 on its outer end, with a helical expanding spring 8| circumposed on the shank l8 and compressed between the related wheel disc and the head 85, whereby the locking disc is is normally retracted out of clamping engagement with the brake shoe web 59 and the head 86 extends outwardly from the related wheel disc and into the path of a related actuating shoe 13 having a rounded approach end 14, as in the embodiment of Figures 2 and 3, whereby the locks are pressed inwardly by the shoes 13 to engage opposite sides of the brake shoe web 59. As the heads 85 pass beyond the actuating shoes 13, the springs 8 I retract the locking discs 19 from the brake shoe web 59 and into the recesses 15. In the impressed position of the locks, the heads 80 seat in the recesses 17.

What is claimed is:

1. In a machine for grinding off the lining of an arcuate brake shoe, a base, a carriage mounted on said base for endwise movement relative to said base, a grinding wheel mounted stationarily at one end of the base and the carriage, a transverse shaft journaled on said carriage, means operatively connected to said shaft for rotating said shaft, a feed wheel fixed on one end of said shaft in the plane of said grinding Wheel, said feed wheel comprising a pair of axially spaced discs having peripheral edges on which a brake shoe is adapted to be circumferentially engaged with the web of the shoe extending radially inwardly from the shoe into the space between the discs, first securing means on said discs for removably securing the brake shoe on the peripheral edges of the discs, and second securing means on said discs engageable with 0pposite sides of the shoe web, adjusting means connected between said base and said carriage for adjusting said carriage endwise on the base for engaging the lining of the brake shoe with the grinding wheel, said second securing means comprising radial pivot pins on the peripheral edges of the discs, locking discs mounted on said pivot pins to swing toward and away from adjacent sides of the shoe web, and locking members on said carriage extending along opposite sides of said feed wheel and engageable with the locking discs to hold the locking discs in engagement with the shoe web and against shifting of the shoe axially with respect to the feed wheel discs.

2. In a machine for grinding off the lining of an arcuate brake shoe, a base, a carriage mounted on said base for endwise movement relative to said base, a grinding wheel mounted stationarily at one end of the base and the carriage, a transverse shaft journaled on said carriage, means operatively connected to said shaft for rotating said shaft, a feed wheel fixed on one end of said shaft in the plane of said grinding wheel, said feed wheel comprising a pair of axially spaced discs having peripheral edges on which a brake shoe is adapted to be circumferentially engaged with the web of the shoe extending radially inwardly from the shoe into the space between the discs, first securing means on said discs for removably securing the brake shoe on the peripheral edges of the discs, and second securing means on said discs engageable with opposite sides of the shoe web, adjusting means connected between said base and said carriage for adjusting said carriage endwise on the base for engaging the lining of the brake shoe with the grinding wheel, sed first securing means comprising magnets circumferentially spaced around the peripheral edges of said discs, said second securing means comprising radial pivot pins on the peripheral edges of the discs, locking discs mounted on said pivot pins to swing toward and away from adjacent sides of the shoe web, and locking members on said carriage extending along opposite sides of said feed wheel and engageable with the locking discs to hold the locking discs in engagement with the shoe web and against sh fting of the shoe axially with respect to the feed wheel discs.

3. In a machine for grin-ding off the lining of an arcuate brake shoe, a base, a carriage mounted on said base for endwise movement relative to said base, a grinding wheel mounted stationarily at one end of the base and the carriage, a transverse shaft journaled on said carriage, means operatively connected to said shaft for rotating said shaft, a feed wheel fixed on one end of said shaft in the plane of said grinding wheel, said feed wheel comprising a pair of axially spaced discs having peripheral edges on which a brake shoe is adapted to be circumferentially engaged with the web of the shoe extending radially inwardly from the shoe into the space between the discs, first securing means on said discs for removably securing the brake shoe on'the peripheral edges of the discs, and second securing means on said discs engageable with opposite sides of the shoe web, adjusting means connected between said base and said carriage for adjusting said carriage endwise on the base for engaging the lining of the brake shoe with the grinding wheel, said carriage having an ejecting lever pivoted thereon having a free end portion positioned between the feed wheel discs, said free end portion being arranged to be engaged by the brake shoe web as the feed wheel is rotated so as to disengage said first and second securing means and free the brake shoe from the peripheral edges of the feed wheel discs.

FRANK A. HARPER. JOHN M. GRAHAM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,548,563 Spencer Aug. 4, 1925 1,844,073 Putnam Feb. 9, 1932 1,952,130 Harrison Mar. 27, 1934 2,170,672 Anderson Aug. 22, 1939 

